Citoquina e Troponina-I em disfunçao cardíaca após cirurgia de revascularizaçäo miocárdica com circulaçäo extracorpórea / Cytokines and troponin-I in cardiac dysfunction after coronary artery grafting with cardiopulmonary bypass

ABSTRACT

OBJECTIVE: The association between cytokines and troponin-I with cardiac function after cardiac surgery with cardiopulmonary bypass remains a topic of continued investigation. METHODS: Serial measurements, within 24h following surgery, of tumor necrosis factor-alpha, its soluble receptors, and troponin-I were performed in patients with normal ejection fraction undergoing coronary artery bypass grafting. Ejection fraction was measured by radioisotopic ventriculography preoperatively, at 24h and at day 7 postoperatively. RESULTS: Of 19 patients studied (59 + or - 8.5 years), 10 (group 1) showed no changes in ejection fraction, 53 + or - 8 percent to 55 + or - 7 percent, and 9 (group 2) had a decrease in ejection fraction, 60 + or - 11 percent to 47 + or -11 percent (p=0.015) before and 24h after coronary artery bypass grafting, respectively. All immunological variables, except tumor necrosis factor-alpha soluble receptor I at 3h postoperation (5.5 + or - 0.5 in group 1 versus 5.9 + or - 0.2 pg/ml in group 2; p=0.048), were similar between groups. Postoperative troponin-I had an inverse correlation with ejection fraction at 24h (r= -0.44). CONCLUSIONS: Inflammatory activity, assessed based on tumor necrosis factor-alpha and its receptors, appears to play a minor role in cardiac dysfunction after cardiac surgery. Troponin I levels are inversely associated with early postoperative ejection fraction